The present disclosure relates generally to communication networks, and more particularly, to multicast routing.
Traditional Internet Protocol (IP) communication allows a host to send packets to a single host (unicast transmission) or to all hosts (broadcast transmission). To support a demand to provide applications such as audio and video conference calls, audio broadcasting, and video broadcasting that involve high data rate transmission to multiple hosts, a third routing technique has evolved, multicast routing. In multicast routing, a host sends packets to a subset of all hosts as a group transmission.
Multicast routing is widely deployed and continues to gain popularity with the advent of multimedia programs and the proliferation of Internet applications. Many multicast-based applications require delivery of large amounts of time sensitive and loss sensitive data simultaneously to large audiences. For these applications, a high degree of multicast resilience is desired to provide near-zero packet loss. In order to achieve this resilience, multicast traffic is split into multiple data streams which are sent over diverse paths. In the case of a failure on one path, the multicast traffic is still available via another path. The multiple data streams, however, result in duplicate packets which increase bandwidth usage and need to be properly discarded when the streams merge.
Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.